TSA screeners are working without pay and some are not doing their jobs properly. A growing number are involved in an informal sick out, causing longer lines.
We already have a shortage of air traffic controllers. One in five are eligible for retirement. If a significant number of them choose to retire rather than stick out the shutdown, we will have a long term problem, especially as the new apprentices in training are also likely to quit.
They have also furloughed all aviation safety inspectors, although they’re being called in without pay as needed.
Tl;dr - if you don’t have to fly right now, don’t.
Other effects: Affordable housing contracts are not being renewed. Nobody has been turned out onto the streets yet, but landlords are cutting back on maintenance.
If the shutdown passes January 20, while food stamp recipients will get money for February (early), they may not get it for March.
FEMA will not have funding after January 31. Some people are still waiting for roof repairs they now won’t get.
The Coast Guard has almost no money left, which, oh! That affects border security. Hey, drug smugglers? All ya need to do is get in a boat. It will also affect safety.
Tl;dr - yes, people are going to die, and we may have a major air disaster. Or another terrorist attack. And more drugs getting into the country.
Yet, 75% of Republicans still support the wall…over American lives.